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arXiv · 2012.05812

A first comparison of Kinetic Field Theory with Eulerian Standard Perturbation Theory

Elena Kozlikin·Robert Lilow·Felix Fabis·Matthias Bartelmann
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Abstract

We present a detailed comparison of the newly developed particle-based Kinetic Field Theory framework for cosmic large-scale structure formation with the established formalism of Eulerian Standard Perturbation Theory. We highlight the qualitative differences of both approaches by a comparative analysis of the respective equations of motion and implementation of initial conditions. A natural starting point for a first quantitative comparison is given by the non-interacting regime of free-streaming kinematics. Our results suggest that Kinetic Field Theory contains a complete resummation of Standard Perturbation Theory in this regime. We further show that the exact free-streaming solution of Kinetic Field Theory can not be recovered in any finite order of Standard Perturbation Theory. Kinetic Field Theory should therefore provide a better starting point for perturbative treatments of non-linear structure formation.

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Elena Kozlikin, Robert Lilow, Felix Fabis, Matthias Bartelmann. 2020-12-02. A first comparison of Kinetic Field Theory with Eulerian Standard Perturbation Theory. https://doi.org/10.1088/1475-7516/2021/06/035

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